Question 1: Describe the process of how a river forms from the source to the mouth.

Answer: A river begins at its source, often in the mountains or hills, where water from rainfall or melting snow collects. It flows downhill due to gravity, gaining volume as it collects tributaries. The river then travels through various landscapes, gradually widening, until it reaches its mouth, where it deposits its load into a sea, ocean, or lake.

Question 2: List and briefly explain three key features found along a river's course.

Answer: 1. **Waterfall**: A sudden drop in the river caused by erosion of hard rock over softer rock. 2. **Meander**: A winding curve or bend in the river formed by lateral erosion. 3. **Floodplain**: A flat area surrounding the river, which floods periodically and is formed by deposition of sediments.

Question 3: Explain how the processes of erosion and deposition shape the features of a river valley.

Answer: Erosion occurs when the river wears away the land through hydraulic action, abrasion, and attrition, carving out features like V-shaped valleys in the upper course. In the lower course, deposition takes place when the river loses energy, depositing sediments and forming features such as floodplains and deltas. Together, these processes continually modify the landscape of the river valley.

Question 4: Imagine a river flowing from the mountains to the sea. Describe how its speed and load (materials carried) change along its course.

Answer: The river's speed is generally fastest in the upper course due to steep gradients and narrow channels. As it moves downstream, the gradient lessens, and the river slows down. The load carried is larger in the upper course, mainly consisting of large particles like rocks and stones, while downstream, the load becomes smaller and finer as particles are broken down and deposited.

Question 5: Draw a cross-section of a river channel in the middle course, indicating the riverbank, main flow, and bed. Label the features clearly.

Answer: A correct sketch would show a wide, relatively shallow channel with gently sloping banks, a main flow of water in the center, and a riverbed of mixed sediments. The labels should include 'bank,' 'main flow,' and 'riverbed.'

Question 6: Identify and explain two human activities that can affect river systems negatively.

Answer: 1. **Deforestation**: Removing trees near rivers increases runoff and erosion, leading to more sediment in the river and increased flood risk. 2. **Urbanization**: Building cities and roads increases surface runoff and reduces natural absorption, causing more frequent and severe flooding, as well as water pollution.

Question 7: Suggest two ways in which river management can reduce flooding risks in urban areas.

Answer: 1. Creating flood barriers or levees along the riverbanks. 2. Restoring natural floodplains to allow rivers space to overflow safely during high flows.

Question 8: Explain how human activities such as dam construction can impact the natural flow of a river.

Answer: Dams regulate river flow, which can prevent natural flooding and sediment transport downstream. This can lead to reduced nutrient flow, impacting ecosystems, and can cause sediment build-up behind the dam, affecting water quality and river health downstream.

Question 9: Describe the role of a river's delta and how it is formed.

Answer: A delta is a landform at the mouth of a river, formed by the deposition of sediments carried by the river as it enters a standing body of water like a sea or lake. Over time, these deposits build up, creating new land, often characterized by multiple channels and wetlands.